The storage stability of dry or moist tobacco products or non-tobacco snuff products demands that the product is maintained at a sufficiently high and fairly constant pH during the entire storage period. This presents a problem in all products of this type but especially as regards moist products since their pH decreases more rapidly than that of the corresponding dry products. Moreover, moist products can be susceptible to microbial growth.
In most non-smoking (oral) tobacco products a pH-regulating agent is needed to increase the amount of unprotonized nicotine which is absorbable by the mucous membrane. At increased pH bacterial growth is also prevented. Soda (sodium carbonate) is the most common such agent. Soda is cheap and easy to handle. However, soda and other pH-regulating agents used have a plain drawback—they do not endow moist products desired storage capability.
A few days after production, the pH of the moist product starts to drop, albeit slowly. Storage at room temperature may spoil moist snuff in 1-2 months. This problem is normally counteracted by three actions, all of which may be combined. Firstly, the problem may be solved by addition of as much soda as possible. This in reality involves adding soda until the pH reaches a value just below 9. Too basic pH-values would result in damage to the user's mucous membrane in the mouth. Secondly, a solution to the problem may entail keeping the product refrigerated until sold, to slow down the processes leading to a decrease in pH. Thirdly, the storage problem may be overcome by frequent production, thus ensuring that a fresh, newly produced product is at all times available on the market. These actions in most cases yield good quality products, although the actions have their intrinsic limitations. For export purposes, for example, the above-mentioned actions are not sufficient or not possible to carry into effect altogether. Although the state of the art actions described may be used to provide a high quality product, there is room for improvement.